Watch or clock movement with manual and automatic winding mechanism



H. STAMM WATCH OR CLOCK MOVEMENT WITH MA NUAL. AND AUTOMATIC WINDING MECHANISM Filed June 8, .1949

July 22, 1952 E... .LLLLE Patented July 22, 1952 WATCH 'OR CLOCK MOVEMENT WITH MANUAL AND AUTOMATIC 'WIND- ING MECHANISM Heinrich Stamm, Grenchen, Switzerland, as-

signor to Uhrenfabrik Eterna A."G., Grenchen, Switzerland, a joint-stock company of Switzerland Application June 8, 1949, Serial No. 97,879 A In Switzerland August 5, 1948 2 Claims.

This invention relates to winding gears for watch or clock movements with manual and automatic winding mechanism. In such movements it is desirous to uncouple as many gear wheels of the manual winding means as possible during automatic winding, in order to avoid any undesirable loss of force originating from the additional drive of the wheels of the manual winding means.

That aim is also the object of the present invention. The novel winding gear is distinguished by the feature that a first gear wheel is mounted on a swing-out lever, and that the longitudinal axis of the lever and the connecting line between the centres of the first wheel and of a second wheel temporarily in engagement with the first wheel form an angle measured in the direction of rotation of said first wheel, which lies between 90 and 180, elastic means being provided which are just suliicient to guarantee engagement of the two wheels when said wheels are at rest.

The first wheel may constitute the contrate wheel, and the second wheel the ratchet, for

instance.

In a preferred embodiment, the customary click and spring may be used as the abovenamed elastic means, and the click may cooperate with the contrate Wheel instead of the ratchet and may be arranged on the side of the contrate wheel opposite to the place of engagement of the two wheels.

Other objects and features will be apparent, as the following description proceeds, reference being had to the accompanying drawings, whereing the single figure illustrates by way of example one embodiment in a schematic way.

The keyless wheel I which is indirectly connected with the axle of the winding crown in a manner not shown meshes with the contrate wheel 2. The contrate wheel 2 is mounted on a swing-out lever 3 rotatable around an axis 4. By swinging the contrate wheel 2 around the axis 4 it can be brought into mesh with the ratchet 5, wherein it is slightly held by a click I rotatably mounted as at 6 and loaded by a spring 8.

The rest position of the above-described mechanism, at which the contrate wheel 2 is held in mesh with the ratchet by means of the click 1 and the spring 8, and to which the contrate wheel 2 is always returned, is shown in full lines. If the manual winding mechanismis operated, and its rotation is transmitted to the contrate wheel 2, the following]parallelogram of forces applied to the center of gravity of the swinging parts (lever 3 and contrate wheel 2) is obtained, the turning moments being neglected.

In the direction of rotation of the keyless Wheel I as indicated by arrow I, a force A is transmitted to the center of gravity S by the keyless wheel I, while a force B is exerted on the contrate wheel 2 by the ratchet 5 on transmitting rotation from the contrate wheel '2 (arrow II) to the ratchet '5 (arrow III). A resultant C is obtained, acting on the lever 3 in such a way that the contrate wheel 2 is still more pressed against the ratchet 5, so that engagement between the two wheels is guaranteed (arrow IV). In this way, rotation of the manual winding means is transmitted to the ratchet 5 and to the barrel in a manner not shown.

If the watch or clock movement is wound up by means of the automatic winding mechanism by an oscillating centrifugal weight, the rotation of the latter is transmitted to the ratchet 5 in the direction of the arrow III in a manner not shown. Due to the ratchet 5 being now a driving part and the contrate wheel 2 a driven part, the forces applied to the common center of gravity of the contrate wheel 2 and the lever 3 are as follows:

A force D originating from the engagement of ratchet 5 with the contrate wheel 2, and a force E originating from the engagement of the contrate wheel 2 with the keyless wheel I, both forces resulting in a resultant F rotating the lever 3 and the contrate wheel 2 in the direction of arrow V.

The influence of the spring 8 may be neglected in that its intensity and its origin are chosen in such a way that it is just suflicient to maintain or to reestablish the engagement of the contrate wheel and the ratchet on the gear wheels being at rest.

The swinging of the lever 3 together with the contrate wheel 2 under the influence of the resultant F results in a disengaging of the contrate wheel 2 from the ratchet 5, and all other parts of the manual winding mechanism are thereby uncoupled during automatic winding.

It is understood that the above-mentioned relations of forces are dependent on the direction of rotation and the mutual position of the several gears and the longitudinal lever axis. Considering the fact that On manual winding the component of force B will always be greater than the component of force A, and that on automatic winding, the component of force E is always greater than the component of force D, it will be understood that the conditions desired always occur when the angle measured in the direction of rotation of the contrate wheel 2 between the longitudinal lever axis and the connecting line between the centers'of the contrate:

wheel 2 and the ratchet 5 lies b'etween-QOTand:

It is understood that theswing outcoupling according to the invention,maybe arrangediat.

bodiment of my inventioml do not wish to un- 2 necessarily limit the scoperof this invention, but reserve the right to make modificationsv and rearrangements of the severalparts as may come within the purviewofrthe accompanying claims. v What I claim. is:

1. In a winding gear for watch or clock movements with manual and automatic winding mechanism, a swing-out lever, a first gear Wheel mounted on said swing-out lever, a second wheel temporarily in engagement with said first gear wheel, the longitudinal axis of said swing-out lever and the connecting line between the centers of saidwheels forming an anglemeasured in the direction of rotation of said first wheel, which lies between 90 and 180, and elastic'means just suflicient to guarantee engagement of said two wheels when said wheels are at rest.

2; Ina winding gear according to claim 1, said fitstwheellconstituting the contrate wheel and the second wheel the ratchet.

HEINRICH STAMM.

REFERENCES CITED The following references are of record in the file: of. this: patent;

FOREIGN PATENTS Number Country Date 156,803 Switzerland Nov. 1, 1932 161,352 Switzerland J.uly 1, 1933 216,720: Switzerland's; Jan. 5-, 1942 5532,9861 Germany a, Feb; 19, 193.4 

